Spacecraft films Pluto’s largest moon in orbit

Pluto and its largest moon, Charon, whirl around each other in images that NASA released August 8. When NASA’s New Horizons spacecraft snapped these photos last month, the probe was roughly 10 times as far from Earth as it was from Pluto. It is scheduled to rendezvous with the dwarf planet next summer.

At one-twelfth the mass of Pluto, Charon is the most massive moon in the solar system in comparison with its host (dwarf) planet. All that mass yanks Pluto around a point that’s above the planet’s surface, leading some to argue that the duo should be classified as a “binary planet.”

MOON DANCE Charon (faint spot) almost completes one orbit around Pluto (bright spot) in a series of images taken by the New Horizons spacecraft. The probe was roughly 425 million kilometers from Pluto when it took these images.Credit: NASA, Johns Hopkins University Applied Physics Laboratory, Southwest Research Institute